Deterministic MME

Simple ensemble mean

Biased ensemble mean

where, is the biased ensemble mean, N number of models, is the ith model forecast out of N models.

Bias-corrected ensemble mean

The simple ensemble method with bias-corrected data is defined as

?is the bias-corrected ensemble mean,??is the mean of ith forecast over the training period,?is the observed mean over the training period. The systematic errors for forecast models can be removed due to anomaly term, (), which accounts model's own seasonal climatology.